This study validated the Adverse Childhood Experiences International Questionnaire (ACE-IQ) in Nigeria by comparing it with the Childhood Trauma Questionnaire (CTQ) among 253 prison inmates. Significant correlations were found between the ACE-IQ and CTQ scores, indicating that ACE-IQ is a reliable measure for assessing childhood trauma. The findings suggest that male, younger, less educated, and divorced inmates reported higher adverse childhood experiences, and the study emphasizes the need for continued research in the area of childhood trauma.